Oaxacaquarius

Thank you chem geek -- this is very helpful!

I use the dichlor/bleach method so many on this forum recommend. I am happy with it too. But, lately, I have been trying to find a store that sells unexpired Clorox, to no avail. The usual big box stores are all selling Clorox that is at least one month expired (base on the printed codes on the bottle), and I have read that the bleach in Clorox loses about 1% strength per month after the expiration date. (I am not sure if this is true and would like to hear from our member chemists.) The grocery stores around here (Arlington VA) are no better. Are there any good online sources? The pool supply places here (and many online) tell me I shouldn't even use Clorox -- see for example: http://www.olympichottub.com/hot-tubs-sauna-blog/2012/09/hot-tub-water-care-never-use-chlorox-in-your-hot-tub/ I don't believe this. But I am frustrated with not being able to find decent (unexpired), regular clorox around here. This has been going on for the past two months. Does anyone know of a good online source, or have any other tips? I have in the meantime been subtracting 1% beach strength for every 30 days past the expiration date when making calculations using the pool calculator. But I am not sure if I want to be doing this after the Clorox is a couple of months past the expiration date. I would think that the higher pH to bleach ratio by volume in the clorox will start to catch up with me and make things harder to balance.

Thank you Chem Geek! The FC did come down -- to 6 ppm. I have the CH at 140 ppm now. The pH is 7.8 (ish) judging from the Taylor Kit, and turns to 7.6 with one drop of the acid demand test solution. My TA is at 70 ppm. For my 175 gallon tub, I have calculated that I need to add 0.21 oz. of Sodium Bisulfate (93.2%) to hit my target of 7.6. But I know that you say I should be targeting a lower TA (between 50-60 ppm), rather than thinking about hitting my pH target, which I can always raise later if necessary by aerating. I will add the dry acid until I get my TA in range (between 50-60 ppm) and pH to 7.6, and then add the Gentle Spa (4 ounces). If you were me, how much dry acid would you add at this point? 0.21 ounces is less than one Tbs, so I assume that I can add it all at once while aerating. But perhaps you would suggest that I try to shoot lower than my ultimate target (add more dry acid than this amount), in anticipation of a rise in pH? For example, if I shoot for a pH of 7.2 now (by adding .4 ounces (by weight) of dry acid, and trust that aerating will bring it up to 7.6 in good time -- am I more likely to hit my target TA of 50-60 ppm, or would I risk reducing my TA too much and "disturb the balance in the Force." I simply do not yet have a sense of the ebb and flow of this process, nor how the dynamic changes when I cross beyond certain critical TA boundaries.

I just re-tested the water with a Taylor kit after reaching my target temperature of 104 degrees. TA= 80 pH= 7.6 CH = 110 FC = 17 (still, after shocking last night). When it drops to FC =3, I was hoping to get in the tub. I am aerating now and waiting. I have not added any Borates or Boric Acid (nor Gentle Spa). I am reticent to reduce my TA at this point because everything seems close to balanced. I am considering adding 0.5 ounces of calcium chloride. Also - I followed the Pool Calculator and added 0.4 oz (by weight) of dichlor to raise my FC from 0 to 10, But I am at 17. How is this possible? And is it a problem, or should I just wait and let it slowly drop? Does this mean that I have added 17 ppm of dichlor? I want to keep my CYA at 20, so I am trying to keep an accurate count of how much dichlor I am adding before switching to bleach.) Any advice for me at this stage?

I still have one question about Gentle Spa. Nitro (in his "Guide to Water Maintenance" post) writes: "Lastly, there is one more thing I haven't mentioned that you can add to your tub that will help buffer your pH, Borates. The easiest way to add Borates to your tub is to get a product called Gentle Spa. It is pH balanced, so there is no need to add acid to counter balance it. The ideal amount is ~50 ppm, and only needs to be added once per water change. That will help keep your pH from drifting from aeration. Not to mention, actually make your water feel silkier. I highly recommend it." If it is pH balanced, why do you suppose people have reported that it raises pH? (I bought, but have not yet added, Gentle Spa after reading Nitro's recommendation, but before reading your response above. Now I am feeling reluctant to add it. You are recommending boric acid -- would Mule Team 20 work? Or is the quality of this source to impure?

I found an old post of yours from April 27 2010 in a thread started by Nitro on "Lowering Total Alkalinity." You write, "Odds are, after switching to bleach after a week or so of Dichlor that you will need a low TA of perhaps 50-60 ppm. If you still find the rate of pH rise too high, you can also use 50 ppm Borates." Thank you!

Thanks for replying Chem Geek. I am curious -- why a TA of 50 ppm?

Does anyone have any advice to offer? i am at 95 degrees now.

I have just drained and refilled my 170 gallon outdoor spa and am waiting for the temperature to rise to 104 degrees (where I like it). It's currently at 60 degrees and rising as it should. My question is when, and in which order, I should begin adding the following chemicals. (I am following ChemGeek's method and using the Pool Calculator. Also I used a Taylor kit to check my current measures.) FC = 0 (want to add dichlor to 10 ppm (eventually adding enough dichlor over the week to get me to a CYA of 20, thus approximately 22 ppm of dichlor, then all regular 6% Clorox bleach from there. pH = 7.6 (out of the tap; it's nice and easy). I want to keep it there. TA = 70 (I want 80, so I'll .4 oz --by weight -- of baking soda. CH = 100 (I want to raise it to 160, so I'll add 2.3 oz -- by volume -- of calcium chloride dihydrate. Borate is, I assume 0 -- I have no way of measuring for sure -- but it is a fresh fill. I am adding Gentle Spa per directions on bottle to get to 50 ppm (and leaving it at that until the next drain and refill. According to PoolMath's calculatior, this should give me balanced spa water at 104 degrees in my 170 gallon spa. If any of this sounds off, please let me know. But I am wondering if I should start adding the sanitizer (dichlor) at some point before my water temperature reaches 104 (tomorrow night, probably) since my FC = 0 and bacteria multiply quickly -- especially in warmer water. Also, does the sequence in which I add these various chemicals matter? I assume I should try to balance the TA first with the baking soda, then add the dichlor to raise the FC (initial shock at 10) , then the calcium chloride dihydrate, and finally the Gentle Spa (with Borates). Does this sound right? And if so, at what temperatures -- ideally -- would I add each? I am new to all of this. I apologize if this sounds like an ignorant raft of questions.